Derek Abbott. That was the next name I wrote down. I underlined it twice.

I hadn’t spoken to him at all so far, and Hawthorne had also done what Deputy Chief Torode had told him and kept away from his old enemy. Even so, Derek Abbott was definitely involved. Quite apart from his own unpleasant background, he had been close to le Mesurier, working as his financial adviser until the two of them had fallen out. It was Anne Cleary who had provided this information and it still had to be corroborated, but for the moment I assumed it was true. There had been a disagreement about money. Derek Abbott was about to be fired. He was an obvious suspect, but even so I really hoped that he had nothing to do with the crime. I had known from the start that he was going to be a major problem for me. It would have been better if I’d never heard of him at all.

Paedophiles are not at all easy to write about because, at the end of the day, what is there to say? They’re sick. They’re disgusting. They’re evil! We all know that and I’d have to be out of my mind to write anything positive about such a man even if he was an accomplished pianist, a great raconteur, a philanthropist. Who would care? The crime is so uniquely unpleasant that it’s like a black hole, sucking everything else into it, and as I sat on my bed in my hotel room I was annoyed that when I did write the book he would end up being in it. What Abbott represented was completely at odds with everything I would enjoy writing about: blue telephone boxes, beaches and fortifications, seagulls, miniature steak and kidney puddings, ginger-haired taxi drivers.

It was also quite likely that Abbott was the one who had killed le Mesurier. Despite his crippled leg, he was a large man and could easily have stunned him – perhaps with his walking stick – and then forced him into that chair. He had a motive. He’d been there on the night of the crime. But if Derek Abbott was revealed to be the killer at the end of the book, who would actually care? If you read Agatha Christie, you may have noticed that every single one of her killers manages to elicit a modicum of sympathy. You may not approve of what they’ve done, but you understand it. Derek Abbott was beyond the pale.